一种基于FFT算法M-APSK信号载波参数联合检测

Joint detection of M-APSK signal carrier parameters based on FFT algorithm

随着卫星通信业务的发展,高阶调制技术逐渐应用于卫星通信中,但载波频率和相位偏差对诸如M-APSK等高阶调制信号的影响很大。在回顾载波同步算法理论的基础上,分析了载波频率和相位偏差对APSK信号系统的影响,采用了一种基于最大似然(ML)准则的数据辅助(DA)载波同步算法,并使用FFT快速运算和三线插值法,对频率偏差和相位偏差进行了联合检测。研究表明,该算法在同步性能和实现复杂度上的性能都比较优越。该算法对卫星通信高阶调制M-APSK信号的同步技术提供了一定的参考价值。

With the development of satellite communication service, high order modulation technology is gradually applied to satellite communications. However, the carrier frequency and phase offsets exert e- normous influence on the high order modulation signals such as M-APSK. Theory of carrier synchroniza- tion was firstly reviewed, and the impact of the carrier frequency and phase offsets on APSK analyzed. A data-aided （DA） carrier synchronization algorithm based on maximum likelihood （ML） was proposed, and the fast operation of FFT and triple-amplitude-line interpolation were used to jointly detect the carrier fre- quency and phase offsets. Simulation results show that the algorithm performs well on synchronization performance as well as realization complexity, which is helpful to promote the M-APSK signal synchroni- zation technology for satellite communication high order modulation.